Paleonews

Il blog dedicato ai Paleontologi !!!!

2009-06-01 – Lyme Regis, UK: trovato un nuovo Plesiosauro (new Plesiosaur)

Info in italiano: LaRepubblica

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Found: The Loch Ness monster –

that lived in the English Channel and died more than 200million years ago

By Eddie Wrenn
Last updated at 8:46 AM on 01st June 2009

 

 

 

It roamed the English channel more than 200 million years ago.

And now the prehistoric monster has surfaced once more – in the limestone of Lyme Regis’s famous ‘Jurassic Coast’.

Excited archaeologists discovered the Loch Ness-style creature on the beach and have spent months piecing together a giant jigsaw composed of dozens of old bones to reveal the 12ft-long plesiosaur.

The Plesiosaur was discovered by archeologists at Monmouth beach in Lyme Regis - known as England's 'Jurassic coast'

The Plesiosaur was discovered by archeologists at Monmouth beach in Lyme Regis – known as England’s ‘Jurassic coast’

The famous 1934 hoax picture, which helped spread the Loch Ness legendThe monster: The famous 1934 hoax picture, which helped spread the Loch Ness legend

The marine reptile hunted the oceans with a long thin neck and tail, four large flippers and razor-sharp teeth.

It existed during the Jurassic period about 150 to 200 million years ago when what is now the Channel was a shallow, tropical sea.

The remains were discovered by fossil hunter Tracey Marler under rocks on Monmouth Beach near Lyme Regis, Dorset.

She first found a single bone in limestone. She and partner Chris Moore, an expert in fossils, returned to the scene and they found four more bones.

As experts examined the bones in detail, they were surprised to see teeth marks from where a predator dinosaur would have feasted on the carcass of the ‘lake monster’.

 

 

Fragments: The skeleton is 70 per cent complete and will soon go on display to the publicFragments: The skeleton is 70 per cent complete and will soon go on display to the public

After further excavation about 150 vertebrae bones and parts of its skull and jaw, with one tooth remaining, were uncovered.

Mr Moore said: ‘It came out in pieces but you could clearly see how it looked.

‘The tail bone was in position, and some of the back bones were completely in place where they should be and the neck bone was there as well.

‘You could see some of the bones had actually been chewed up a bit.

‘There are teeth marks and you can see how the skeleton had been torn apart by some other nasty marine reptile.’

 

 

More…

 

Mr Moore added: ‘Their predator would have been the ichthyosaur which was carnivorous.’

Natural England worked closely with the Jurassic Coast World Heritage Site team to carefully extract the fossils.

The alternative of leaving it could have led to it being destroyed by ill-informed collectors or eventually being washed away and eroded by the sea.

Richard Edmonds, science manager for the Jurassic Coast World Heritage Site, said: ‘There was a risk that we could have damaged the pavement by the act of removing the fossil.

‘Plesiosaur remains are rare. There are only 10 known examples of complete or even partial skeletons of this species.

‘I have been doing this for 30-odd years and I have only ever found the odd bone.

‘The specimen could not have been in a more sensitive location, in the famous and iconic ammonite pavement.’

It is hoped the skeleton, which is 70 per cent complete, will go on public display at the Lyme Regis Museum.

source: dailymail.co.uk

giugno 1, 2009 Posted by | - Plesiosauri, - Rettili, 2 Jurassic / Giurassico, An. Vertebrates, Europa, Lang. - Italiano, Mesozoic, P - Ritrovamenti fossili, Paleontology / Paleontologia | , , , , | Lascia un commento

2009-05-31 – Libro: “Alla ricerca dei fossili nei monti e nelle cave del Lario e del Ceresio”

I fossili del Lario

 Como –  Presentato «Alla ricerca dei fossili nei monti e nelle cave del Lario e del Ceresio» frutto del lavoro del ricercatore comasco Attilio Selva .

  Con questa nuova pubblicazione, che si presenta come primo lavoro organico di analisi paleontologica del nostro territorio, proseguono le iniziative dell’assessorato provinciale Ecologia e ambiente, in collaborazione con quello alla Cultura, per far conoscere più a fondo la realtà  storica in cui viviamo. «Lo sviluppo sostenibile della nostra provincia passa anche dal nostro impegno a preservare le bellezze e la memoria del nostro territorio – ha spiegato l’assessore provinciale all’Ambiente Paolo Mascetti – ed è proprio la conoscenza del luogo in cui viviamo che quest’opera vuole trasmetterci, raccontandoci i dettagli della nostra storia passata». La pubblicazione ripercorre, in ordine rigorosamente cronologico, la geografica dei giacimenti di fossili situati lungo le rive del Lario, del Ceresio e nelle valli interne. Nelle 235 pagine trova così spazio il famoso Lariosauro, rinvenuto per la prima volta nell’Ottocento, ma anche siti di pregio a livello internazionale, come Osteno, vero e proprio caso di studio perchè le sue rocce sono state in grado di conservare anche le parti molli di animali vissuti nel Giurassico. Un viaggio lungo il giacimento carbonifero della Val Sanagra, dove sono stati rinvenuti i primi semi di conifera mai apparsi sulla Terra, fino alla Val Rezzo, dove sono stati rinvenuti i fossili di pesci volanti e di barracuda lunghi anche 30 centimetri, per arrivare alle biografie dei personaggi e degli autori che hanno contribuito alla scoperta degli aspetti paleontologici dell’area lariana. «Il pregio di questo libro è che si legge tutto di un fiato – ha commentato l’assessore provinciale alla Cultura Mario Colombo – Ha la capacità  di rendere affascinante la biologia».Il volume è in distribuzione gratuita presso il settore Ecologia della Provincia di Como (villa Gallia), previa prenotazione presso la segreteria dell’assessorato 031/230367. La prossima pubblicazione, già  in cantiere, affronterà  la geologia della provincia di Como.

fonte: http://www.giornaledicomo

maggio 31, 2009 Posted by | - Italia, - Rettili, An. Vertebrates, Europa, Lang. - Italiano, Libri / Books, Paleontology / Paleontologia | , , , , , , , , , , , | Lascia un commento

2009-05-10 – Utah, USA: ritrovata una tartaruga fossile incinta (fossil pregnant turtle)

Rare prehistoric pregnant turtle found in Utah

At least three eggs are visible from the outside of the fossil, and Montana State University researchers this week have been studying images taken from a CT scan in search of others inside.

Montana State graduate student Michael Knell says the turtle was probably about a week from laying her eggs when she died and became entombed for millions of years in sandstone.

The fossil was found in 2006 in a remote part of Grand Staircase-Escalante National Monument. The eggs weren’t discovered until after it sat in storage for two years and was being re-examined by a volunteer.

This image provided Montana State University shows CT technician, Tanya Spence preparing to run a 75 million-year-old turtle fossil through a CT scanner at Deaconess Hospital in Bozeman, Mont. (AP Photo/Montana State University, Kelly Gorham)

This image provided Montana State University shows CT technician, Tanya Spence preparing to run a 75 million-year-old turtle fossil through a CT scanner at Deaconess Hospital in Bozeman, Mont. (AP Photo/Montana State University, Kelly Gorham)

maggio 10, 2009 Posted by | - Rettili, 1 Cretaceo, America Northern, An. Vertebrates, Articolo sc. di riferimento, Mesozoic, P - Preservazione eccezionale, P - Ritrovamenti fossili, Paleontology / Paleontologia, X - Nature | , , , , , , , , , | Lascia un commento

2009-04-09 – Zone BS: Scoperte impronte di rettili risalenti al Triassico (Triassic reptile footprint from Italy)

Paleontologia, scoperte orme fossili nei pressi del lago di Iseo

9 aprile 2009 – Alcune passeggiate fossili di rettili predatori, ritenuti antenati dei dinosauri, sono state rinvenute su una parete di roccia nei pressi del paese di Zone, nei dintorni del lago di Iseo. Le 70 orme, il cui diametro varia dai 12 ai 40 centimetri, a detta del team di paleontologi italiani che le hanno studiate, risalgono al periodo Triassico, approssimativamente a 220 milioni di anni fa. Secondo gli studiosi – che renderanno noti i risultati della loro ricerca, eseguita anche con tecnica laser, il 16 aprile al Museo di Storia naturale di Milano – quelle rinvenute nel Bresciano sono le più grandi, e tra le più antiche, tracce fossili finora scoperte in Italia. I rettili che le hanno lasciate dovrebbero essere dei precursori dei dinosauri e, secondo i paleontologi, per un certo periodo avrebbero coabitato con loro, finendo per trovarsi anche in competizione, fino a esserne soppiantati. La grandezza delle loro orme, dai 12 ai 40 centimetri, potrebbe depistare sulle loro dimensioni, spingendo a ritenerli quasi degli animaletti domestici: in realtà i rettili triassici non appoggiavano a terra tutta la pianta e, dalla distanza tra un passo e un altro, e tra impronte posteriori e anteriori, gli studiosi hanno ricavato l’idea che dovessero raggiungere anche i sei metri di lunghezza. In confronto a rettili contemporanei come i coccodrilli, poi, avevano una maniera di camminare stranamente più evoluta: dalla mancanza della scia di trascinamento della coda, gli studiosi hanno ritenuto che i loro arti erano in posizione verticale sotto il corpo e che quindi camminavano con ventre e coda ben lontani dal terreno. Una tecnica subito imitata dai loro successori, i dinosauri, che li avrebbero poi eliminati. La sfortuna di questi rettili, d’altronde, per gli studiosi, è proprio che “tentarono di diventare dinosauri, senza riuscirci”. E così l’evoluzione li portò all’estinzione. Lo si apprende dall’Ansa. Last Updated ( giovedì, 09 aprile 2009 )

source: http://www.fondazioneitaliani.it/index.php/en/Paleontologia-scoperte-orme-fossili-nei-pressi-del-lago-di-Iseo.html

aprile 9, 2009 Posted by | - Italia, - Rettili, 3 Triassico, An. Vertebrates, Europa, Lang. - Italiano, Mesozoic, P - Impronte, Paleontology / Paleontologia | , , , | Lascia un commento

2009-03-07 – Coahuila, MEX: the oldest chelonid turtle

Oldest sea turtle fossil unveiled in Mexico

“It is the oldest sea turtle of its kind and it belongs to the chelonia family. The oldest specimen of this species up to now was 65 million years old and was found in New Jersey, United States,” the INAH said in a statement.

The fossils of seven sea turtles were found at different sites in Coahuila, the state that Mexican scientists call “the paradise of paleontology.”

The sea turtle inhabited the northern region in the late Cretaceous period, 72 million years ago, and is the ancestor of the present day green turtle, the institute said.

It was one meter (yard) long, 70 centimeters (28 inches) wide and distinguished from other turtles by its rounded head.

source: AFP

marzo 7, 2009 Posted by | - Rettili, 2 Jurassic / Giurassico, America Central, An. Vertebrates, Mesozoic, P - Ritrovamenti fossili, Paleontology / Paleontologia | , , , , , | Lascia un commento

2009-02-14 – Aurorachelys, tartaruga fossile dalla Groenlandia (Greenlad, turtle fossil)

February 13, 2009

Ancient turtle fossil found on Axel Heiberg Island

Shell dates from warm period 90 million years ago

NUNATSIAQ NEWS

Geologists from the University of Rochester have uncovered a 90 million-year-old fossil of a tropical freshwater Asian turtle in Nunavut’s High Arctic.

The fossil was found in a slab of ancient basalt on Axel Heiberg Island.

The turtle, dubbed Aurorachelys, or aurora turtle, lived in the region 90 million years ago when polar temperatures averaged above 14 C, similar to those found in today’s northern Florida.


2009-02-14-aurorachelys
Turtles swam in Nunavut’s High Arctic 90 million years ago, say geologists who announced the find of this fossil turtle shell this week.
(PHOTO COURTESY OF THE UNIVERSITY OF ROCHESTER)

A paper on the fossil, published in the Feb. 1 journal Geology, suggests that carbon dioxide pouring into the atmosphere from volcanic activity during that period may have caused a “super-greenhouse” effect, boosting temperatures in the polar region.

“We’re talking about extremely warm, ice-free conditions in the Arctic region, allowing migrations across the pole,” said John Tarduno, professor of geophysics at the University of Rochester and leader of the team that found the turtle fossil, in a news release on the find.

The turtle resembles a kind of freshwater turtle found in Mongolia, so its presence in the High Arctic suggests that it may have migrated from Asia to North America by floating on a freshwater layer on top of the then-warm, salty Arctic Ocean.

Tarduno’s team found the fossil in 2006 when they went to the Arctic to study paleo-magnetism- that is, the Earth’s magnetic field in the far distant past.

Tarduno said study of the magnetism in rocks where the fossil was found rules out the possibility that the fossil came from southern waters. The turtle was clearly a native of the area, Tarduno noted.

At the time the aurora turtle lived, the Arctic Ocean was probably even more separated from the global oceanic circulation system than it is today, Tarduno said, and rivers would have poured fresh water into the ancient sea.

Fresh water is lighter than sea water, so Tarduno thinks fresh water may have rested on top of the salty water, allowing a freshwater animal such as the aurora turtle to migrate.

According to the news release, Tarduno also believes volcanoes could have produced a series of islands along an underwater mountain range in the Arctic Ocean called the Alpha Ridge.

If the ridge poked out above the surface of the water at one time, it would have given the turtles and other species the ability to island-hop all the way from ancient Russia to Canada, Tarduno said.

In recent years, Tarduno has uncovered fossils of other warm-water species in the High Arctic, such as crocodile-like beasts, which once thrived there 90 million years ago.

source: http://www.nunatsiaq.com/news/climate/90213_1907.html

febbraio 14, 2009 Posted by | - Rettili, 1 Cretaceo, An. Vertebrates, Mesozoic, P - Ritrovamenti fossili, Paleontology / Paleontologia | , , , , , , | Lascia un commento

2009-02-12 – Perù: Impronte di Dinosauri (Dinosaur footprints, Dinosaurier)

Dinosaur footprints, fossils found in central Peru

Lima, February 10, 2009
Hundreds of footprints and the fossilised remains of various prehistoric animals, probably dinosaurs that lived 120 million years ago, have been discovered in the Ancash region of central Peru.

The find came when the Antamina mining company, which is owned by BHP Billiton and Xstrata, among other partners, was building a road from its camp at Yanacancha to the Conococha crossroads, in Huari province, some 400 km northeast of Lima.

The company confirmed that a preliminary examination of the site, which is 4,600 metres above sea level, revealed more than 100 footprints made by at least 12 different types of ancient animals, including marine species, demonstrating that in the distant past the site lay at the bottom of an ancient ocean.

According to calculations by the paleontologists in charge of these finds, the site could date back to the Early Cretaceous Period about 120 million years ago.

Some of the fossils discovered there, the daily El Comercio reported, are from large marine reptiles known as sauropterygians, complete skeletons of which were found.

Other fish-like reptiles called ichthyosaurs were also found there, along with extinct species of crocodiles, flying reptiles called pterosaurs, tortoises and fish, not to mention very well-preserved specimens of assorted invertebrates.

The paleontological work in the area dates back to 2006, when construction on the road began and exposed potentially fossil-bearing layers of sediment, according to an analysis conducted by the Ornithology and Biodiversity Centre, known as Corbi.

The excavations performed to date at the site, which is called Cruz Punta, at Kilometer 80 of the highway, revealed a rocky wall-like formation several dozen metres in length on which there were clear indications of fossilised animal tracks, according to the Corbi study.

source: hindustantimes

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The footprints of a prehistoric animal are clear to see in a rock layer in Peru

The footprints of a prehistoric animal are clear to see in a rock layer in Peru

from: metro.co.uk

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20minuten

Dinosaurier auf 4600 Metern gefunden
20minuten – 15 ore fa
Dabei stiessen die Strassenbauer auf über hundert fossile Abdrücke und Knochen von Dinosaurier-Arten, die vor etwa 120 Millionen Jahren gelebt haben. Bei den Funden konnten zwölf verschiedene Arten unterschieden werden, darunter fleischfressende

febbraio 12, 2009 Posted by | - Plesiosauri, - Pterosauri, - R. Dinosauri, - Rettili, 1 Cretaceo, America Central, An. Vertebrates, Lang. - German, Mesozoic, P - Impronte, P - Ritrovamenti fossili, Paleontology / Paleontologia | , , , , , | 2 commenti

2009-02-10 – Steve Sweetman e la paleo-fauna dell’isola di Wight (Britain’s Jurassic Park)

«Jurassic Park» nell’isola di Wight

Scoperte le tracce fossili di un Velociraptor e di altri dinosauri dove suonò Bob Dylan nel 1969

DAL NOSTRO CORRISPONDENTE – LONDRA – I più giovani, forse, ne hanno sentito parlare di quell’ultimo giorno di agosto del 1969, ben 40 anni fa, quando su un prato dell’Isola di Wight migliaia e migliaia di ragazzi della beat-generation si ritrovarono ballare e cantare con Bob Dylan, vestito di bianco, e la sua «Band». Un concerto-festival entrato nella storia della musica e del costume. Bob Dylan non piacque a molti, ci fu chi scrisse su una pietra: qui giace il grande Bob. Fra la folla c’erano un certo John Lennon e un certo Paul Harrison.

SCAVATE TRE TONNELLATE DI TERRA – Oggi l’isola di Wight, al largo di Southampton nella Manica, fa parlare ancora di sé. Ma per ben altre ragioni. Steve Sweetman, dell’università di Portsmouth, ha ritrovato in quattro anni di ricerca le tracce fossili di un velociraptor, il Predatore Veloce del Cretaceo, di un pterosaurus, di tre sauropodi e di almeno quattro dinosauri erbivori, oltre a tre coccodrilli giganti e 48 specie sconosciute di animali. Il paleontologo ha dragato tre tonnellate mezzo di terra partendo da un minuscolo indizio: la mandibola di una salamandra. Che l’Isola di Wight avesse ospitato cento milioni di anni fa una piccola colonia di dinosauri gli scienziati lo avevano già accertato. Ma la scoperta, annunciata ieri, è sorprendente. Se non altro per la quantità del «tesoro» venuto alla luce. Jurassik Park è davvero esistito.

Fabio Cavalera
10 febbraio 2009

fonte: corriere.it

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Dinosaur hunter unearths nearly 50 new species in Britain’s own Jurassic Park

Some 48 new prehistoric species have been unearthed by a British expert from Britain’s own Jurassic Park, including dinosaurs similar to the deadly velociraptor and giant flying pterosaurs.

 

 By Richard Alleyne, Science Correspondent – Last Updated: 10:49PM GMT 09 Feb 2009

febbraio 10, 2009 Posted by | - R. Dinosauri, - Rettili, 1 Cretaceo, An. Vertebrates, Bl - Top posts, Europa, Mesozoic, P - Impronte, P - Ritrovamenti fossili, Paleontology / Paleontologia | , , , , , , , , | Lascia un commento

2009-02-06 – Titanoboa, il serpente più grande di sempre (the greatest fossil snake)

click here for video.

E’ Titanoboa il serpente più grosso del mondo

Viveva 60 milioni di anni fa in Colombia e aveva misure record: 13 metri di lunghezza per oltre una tonnellata di peso. Ossa fossili scoperte da una spedizione internazionale in Colombia
di ALESSIA MANFREDI 

OLTRE una tonnellata di peso distribuita su 13 metri di lunghezza. Misure decisamente oversize, paragonabili ad un Tyrannosaurus Rex, quelle del serpente più lungo del mondo, che, secondo un’équipe internazionale di scienziati, viveva 60 milioni di anni fa in Sud America.

La stazza del biscione giurassico è stata dedotta sulla base di ossa fossili ritrovate dai ricercatori dello Smithsonian Tropical Research Institute a Panama e del Museo di Storia Naturale dell’Università della Florida nel Cerrejon, nella Colombia del Nord.

Battezzato dai suoi scopritori Titanoboa Cerrejonensis, questo rettile gigante misurava 13 metri, pesava 1.140 chili e il suo corpo era largo almeno un metro, scrivono su Nature gli scienziati guidati dal paleontologo Jason Head dell’Università di Toronto-Mississauga. Messa a confronto con quella di una normale anaconda, la sua vertebra risulta enorme.

GUARDA LE FOTO

Il Titanoboa viveva fra 58 e 60 milioni di anni fa, quando il mondo animale si stava ancora riprendendo dall’estinzione di massa che fece scomparire i dinosauri e molte altre specie 65 milioni di anni fa, e potrebbe essere stato il più grande vertebrato non marino sulla Terra.

Le sue impressionanti dimensioni danno anche indicazioni precise sulle temperature dell’ambiente in cui viveva. “Ci sono molti modi in cui l’anatomia di una specie è correlata con l’ambiente su larga scala”, ha spiegato David Polly, geologo dell’Università dell’Indiana, che ha identificato la posizione delle vertebre fossili ritrovate nella miniera di carbone a cielo aperto del Cerrejon ed ha reso possibile ricostruire le misure del rettile. Per sopravvivere, stimano i ricercatori, il mega serpente aveva bisogno di una temperatura media di almeno 30-34 gradi, superiore a quella odierna in quella regione.


Il Titanoboa abitava in una foresta pluviale tropicale e cacciava coccodrilli, tartarughe e pesci. Non era velenoso ed aveva uno stile di vita molto simile a quello delle anaconde dei sistemi fluviali. L’ecosistema in cui viveva era simile a quello dell’Amazzonia di oggi, ma più caldo. “Gli ecosistemi tropicali del Sud America erano sorprendentemente diversi 60 milioni di anni fa”, dice il paleontologo Jonathan Bloch, del Museo di Storia Naturale dell’Università della Florida. “Era una foresta pluviale ma decisamente più calda rispetto a oggi ed i rettili a sangue freddo erano molto molto più grossi rispetto quelli odierni”.

Nella spedizione al Cerrejon, gli scienziati hanno recuperato fossili di vertebre e costole provenienti da 28 esemplari diversi. Prima della scoperta del Titanoboa, il serpente più grosso noto alla scienza era Gigantophis, che viveva 39 milioni di anni fa in Egitto ed era lungo 10 metri.

(4 febbraio 2009)

http://www.repubblica.it/2009/02/sezioni/scienze/serpente-colombia/serpente-colombia/serpente-colombia.html

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Ancient snake’s massive size points to extra hot jungle: study

Last Updated: Wednesday, February 4, 2009 | 1:53 PM ET

Researchers have found the remains of what they are billing as the biggest snake the world has ever known — an animal estimated to be longer than a city bus and heftier than a car.

The boa constrictor-like reptile lived in South America about 60 million years ago and its size provides valuable clues about what the climate was like in the equatorial tropics at that time, said a study published in Thursday’s issue of the journal Nature by an international team of authors that included University of Toronto paleontologist Jason Head.

“If it was around today and it swallowed you, you wouldn’t even be a bulge in its belly,” said Head.

He said he first saw one of the snake’s giant vertebrae, the bones in its backbone, while chatting online with co-author Jonathan Bloch, from the University of Florida, who held them up in front of webcam.

“I jumped out of my seat and got very excited and he started laughing and I started laughing … because it’s just such a mind-bogglingly big animal,” Head recalled.

Based on the size of the snake’s vertebrae — the largest ever for either a living or extinct snake — the researchers estimate that the ancient snake could have grown to be 13 metres long and weigh about 1,135 kilograms.

Head said the largest modern snakes are reticulated pythons, which reach a length of about nine metres, and green anacondas, which can grow to be 7.5 metres long.

Researchers found the vertebrae and ribs for about 28 individual snakes of this species, which was given the name Titanoboa cerrejonensis to indicate its great size and the fact that it was found in the Cerrejon region of northeastern Colombia. The type of pollen found with it suggested that it lived about 58 to 60 million years ago, roughly six to eight million years after the dinosaurs went extinct.

Head said cold-blooded animals such as snakes can’t generate their own heat, so they need an external heat source to power their metabolisms. Because larger animals have slower metabolisms, larger cold-blooded animals need more heat.

Hotter climate lets cold-blooded animals grow

Scientists have already studied the size of snakes living at different temperatures, and found that their maximum size is proportional to the average temperature. Based on what they know about that relationship, as well as the size and environment of the living anaconda, which is similar, the study estimated that the largest specimens of Titanboa would have needed an environment where the average temperature was at least 33 C — about six degrees warmer than equatorial South America is today — in order to survive.

The Titanboa fossils were found in an open pit coal mine, alongside fossilized giant turtles, as well as fossils of primitive crocodiles that the snake likely ate. The snake likely spent most of its time in the water, as anacondas do, Head said.

Fossils from the tropics are difficult to find, Head said, because so much of the area is covered by jungle rather than bare rock or sand. That means there is little data about what the ancient climate was like there.

“Fortunately, the owners of the Cerrejon mine had the presence of mind to be interested in the fossils they were finding,” he said.

The mine owners worked with Carlos Jaramillo of the Smithsonian Tropical Research Institute in Panama and Bloch, who eventually consulted Head because his research specialty is fossil snakes.

http://www.cbc.ca/technology/story/2009/02/04/tech-giant-snake.html

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Times Online

Discovery of 43-Foot Snake Fossil Signals Warmer Tropical Past
Bloomberg – 4 ore fa
The discovery of fossil vertebrae in a coal mine in Cerrejon, Colombia, signifies the largest known snake, one that couldn’t have survived unless temperatures averaged 30 to 34 degrees Celsius, (86 to 93 degrees Fahrenheit), scientists wrote in the
Fossil remains of world’s biggest snake are found International Herald Tribune
Fossil of giant 13-metre snake found in Colombia Irish Times
Los Angeles Times – USA Today – The Associated Press – guardian.co.uk
e altri 335 articoli simili »

http://news.ufl.edu/2009/02/04/largest-snake-fossil/

 

febbraio 6, 2009 Posted by | - Rettili, America Southern, An. Vertebrates, Cenozoic, G - Geographic Distribution, P - Ritrovamenti fossili, Paleontology / Paleontologia | , , , , , , , | Lascia un commento

2009-02-03 – La tartaruga fossile e il polo “tropicale” (Turtle fossil and tropical Artic)

CLIMA: CANADA; FOSSILE TARTARUGA PROVA ANTICO EFFETTO SERRA

L’Artide 90 milioni di anni fa era un posto molto piu’ temperato: senza ghiacci e con passaggio migratorio degli animali preistorici. Lo sostengono alcuni scienziati dopo la scoperta di un fossile di tartaruga asiatica nell’Artide canadese. Secondo i ricercatori, tra cui Donald Brinkman del Royal Tyrell Museum dell’Alberta, la tartaruga tipica della Mongolia, chiamata ‘tartaruga aurora’, con il guscio quasi perfettamente rotondo, esistente all’epoca dei dinosauri e da tempo estinta, avrebbe percorso migliaia di chilometri dal suo habitat originario nelle acque dolci dell’Asia passando non dall’Alaska ma direttamente dal polo Nord. Questo proverebbe che nel polo Nord le temperature in passato erano molto piu’ temperate, al punto da rendere l’Artide un percorso migratorio delle creature preistoriche. Secondo i ricercatori un ‘super effetto serra’, forse originato da eruzioni vulcaniche, causo’ 90 milioni di anni fa un’enorme emissione di anidride carbonica scaldando i poli ed aprendo nuovi passaggi per gli animali migratori, comprese le tartarughe. (ANSA). COR-DI
02/02/2009 19:47

fonte: http://www.ansa.it/ambiente/notizie/notiziari/natura/20090202194734816739.html

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Turtle fossil shows how ‘super-greenhouse effect’ created tropical Arctic

The discovery of a fossilised ancient turtle reveals the North Pole was once “extremely” warm and tropical, scientists said.

Turtle fossil shows how 'super-greenhouse effect' created tropical Arctic
The North Pole: “extremely” warm and tropical millions of years ago Photo: GETTY IMAGES

Animals migrated from Asia to North America directly across the formerly frost-free Arctic Ocean, new evidence shows.

Geologists made the breakthrough after discovering the fossil of a freshwater Asian turtle – dating back millions of years – in Canada.

John Tarduno, a US-based professor of geophysics at the University of Rochester, said: “We’ve known there’s been an interchange of animals between Asia and North America in the late cretaceous period, but this is the first example we have of a fossil in the High Arctic region showing how this migration may have taken place.

“We’re talking about extremely warm, ice-free conditions in the Arctic region, allowing migrations across the pole.”

Numerous rivers from the adjacent continents would have poured fresh water into the ancient Arctic sea, he said.

Fresh water, which is lighter than marine water, may have rested on top of the salty ocean water allowing animals such as the turtle to migrate with relative ease.

The professor, who published his findings in the journal Geology, added: “We found this turtle right on top of the last flood basalts – a large stretch of lava from a series of giant volcanic eruptions.

“That leads us to believe that the warming may have been caused by volcanoes pumping tremendous amounts of carbon dioxide into the Earth’s atmosphere.

“There is evidence that this volcanic activity happened all around the planet – not just the Arctic.

“If it all happened on a short-enough timescale, it could cause a super-greenhouse effect.”

The research team plans to return to the Arctic to look for more fossils.

source: http://www.telegraph.co.uk/earth/environment/climatechange/4419843/Turtle-fossil-shows-how-super-greenhouse-effect-created-tropical-Arctic.html

febbraio 3, 2009 Posted by | - Rettili, 1 Cretaceo, An. Vertebrates, Antartide, Lang. - Italiano, Mesozoic, P - Paleoclimatologia, Paleontology / Paleontologia | , , , , , , , , , | Lascia un commento